Global concerns have been raised regarding the amount of power consumed by currently used incandescent lamps and high pressure sodium vapor lamps, and by extension, the amount of atmospheric CO2 released due to such power consumption. Also incandescent lamps have shorter life span and use hazardous materials, thus attracting high maintenance costs and are non-friendly to ecosystem and unsustainable by nature. Because of this, solid-state based illumination has received attention as an optimum energy-conserving, eco-friendly light source, of future.
The proven unsustainability of conventional incandescent lighting sources has led to the change in energy policies across the world. To combat climate change the European Union has agreed to phase out conventional light sources that are energy inefficient. According to an EU Directive, from 1 Sep. 2009 manufacturers and importers may no longer sell incandescent lamps with an output of 80 W (950 lm) or more or which are frosted and not in Energy Class A. Clear lamps with more than 950 lm must achieve at least Energy Class C, and ones with less than 950 lm at least Energy Class E. Lamps in Energy Classes F and G will be banned from 1 Sep. 2009. For the lighting industry there are already phase-out scenarios for household lighting and lighting in the tertiary sector (street, office and industry lighting) and these scenarios are currently being discussed. The less efficient light sources will start being phased out as early as this year.
Cuba exchanged all incandescent light bulbs for CFLs, and banned the sale and import of them in 2005. Brazil and Venezuela phased out incandescent light bulbs in 2005. In Argentina, selling and importing incandescent light bulbs will be forbidden starting 31 Dec. 2010. In Canada the provincial government has announced intention to ban the sale of incandescent light bulbs by 2012. In USA, federal Clean Energy legislation effectively banned (by January 2014) incandescent bulbs that produce 310-2600 lumens of light. Bulbs outside this range (roughly, light bulbs currently less than 40 Watts or more than 150 Watts) are exempt from the ban. Also exempt are several classes of specialty lights, including appliance lamps, “rough service” bulbs, 3-way, colored lamps, and plant lights.
Philippines, In February 2008, called for a ban of incandescent light bulbs by 2010 in favor of more energy-efficient fluorescent globes to help cut greenhouse gas emissions and household costs during her closing remarks at the Philippine Energy Summit.
Switzerland banned the sale of all light bulbs of the Energy Efficiency Class F and G, which affects a few types of incandescent light bulbs. Most normal light bulbs are of Energy Efficiency Class E, and the Swiss regulation has exceptions for various kinds of special-purpose and decorative bulbs.
The Irish government was the first European Union (EU) member state to ban the sale of incandescent light bulbs. It was later announced that the member states of the EU agreed to a phasing out of incandescent light bulbs by 2012. United Kingdom has enlisted the help of retailers with a voluntary, staged phase out.
In February 2007 the Australian Federal Government announced the introduction of minimum energy performance standards (MEPS) for lighting products.
Though the very unsustainable nature of the incandescent lamps is now well understood by the masses but the alternatives that we currently have e.g. CFLs (compact fluorescent lamps) are also not the best choice.
CFLs, like all fluorescent lamps, contain small amounts of mercury as vapor inside the glass tubing, averaging 4.0 mg per bulb. A broken compact fluorescent lamp will release its mercury content. Safe cleanup of broken compact fluorescent lamps differs from cleanup of conventional broken glass or incandescent bulbs. Because household users in most regions have the option of disposing of these products in the same way they dispose of other solid waste most CFLs are going to municipal solid waste instead of being properly recycled.
Moreover the cost of CFLs is higher than incandescent light bulbs. Typically this extra cost may be repaid in the long-term as CFLs use less energy and have longer operating lives than incandescent bulbs. However, there are some areas where the extra cost of a CFL may never be repaid, typically where bulbs are used relatively infrequently such as in little-used closets and attics. It is also currently not possible to obtain CFL versions of the range of colours and effects. In the past decade, hundreds of Chinese factory workers who manufacture CFLs for export to first world countries were being poisoned and hospitalized because of being exposed to mercury (The Sunday Times, May 3, 2009).
To overcome the economic, environmental and health issues associated with the conventional incandescent lights and CFLs (Compact fluorescent lamps), the alternative solution for illumination purposes, use of environment friendly general illumination fixtures based on smart use of solid-state lighting devices.
Solid-state lighting has the potential to revolutionize the lighting industry. Light-emitting diodes (LEDs)—commonly used in signs, signals and displays—are rapidly evolving to provide light sources for general illumination. This technology holds promise for lower energy consumption and reduced maintenance.
Characteristic Benefits of Solid State Lighting Include:
                1. Long life—LEDs can provide 50,000 hours or more of life, in comparison, an incandescent light bulb lasts approximately 1,000 hours.        2. Energy savings—the best commercial white LED lighting systems provide more than twice the luminous efficacy (lumens per watt) of incandescent lighting. Colored LEDs are especially advantageous for colored lighting applications because filters are not needed.        3. Better quality light output—LEDs have minimum ultraviolet and infrared radiation.        4. Intrinsically safe—LED systems are low voltage and are generally cool to the touch.        5. Smaller flexible light fixtures—The small size of LEDs makes them useful for lighting tight spaces.        6. Durable—LEDs have no filament to break and can withstand vibrations. Last longer than any conventional light source        7. Reduced maintenance costs and energy costs        8. Focused Lighting—Directed light for increased system efficiency, directional resulting in highly controllable optical systems.        9. No moving parts, nothing to break, rupture, shatter, leak or contaminate the environment.        10. Green Technology—They emits no ultraviolet rays, infrared heat, and contains no mercury or lead.        11. Their long life and small size means far less waste.        12. Low Voltage current driven solid-state device operating at voltages as low as 3 VDC.        13. Cold Start Capable no ignition problems in cold environments—even down to −40° C.        
The term “solid state” refers to the fact that light in an LED is emitted from a solid object—a block of semiconductor—rather than from a vacuum or gas tube, as is the case in traditional incandescent light bulbs and fluorescent lamps. Compared to incandescent lighting, however, SSL creates visible light with reduced heat generation or parasitic energy dissipation, similar to that of fluorescent lighting. In addition, its solid-state nature provides for greater resistance to shock, vibration, and wear, thereby increasing its lifespan significantly.
SSL devices are based on the semiconductor diode, When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. This effect is called electroluminescence and the color of the light is determined by the energy gap of the semiconductor. One of the major challenges in using SSL is the management of heat that dissipates from the junction diode. The efficiency of the LED depends largely on its heat-dissipation. The ambient temperature of the surrounding environment has an effect on the performance of the LED by leading to its self-heating. Overdriving it in a high ambient temperature may have an adverse effect on its light-emitting capacity. As the semiconductor die in the LED heats up, the light output of the LED decreases thus reducing its efficiency. Thus over-heating of the LED may lead to a device failure.
The possible approach to compensate for LED self-heating effect is to design the body of fixture panel of the LED lighting device in a way that it dissipates as much heat as possible. The maximum heat dissipation can be achieved by virtue of the design and material of the lighting fixture panel on which the solid-state lighting devices are mounted upon.
Some of the inventions which illustrate various designs of the LED based illumination devices are:
US20080089069 filed by Medendorp teaches a solid state lighting subassembly or fixture which includes an anisotropic heat spreading material. In this invention the said anisotropic heat spreader in thermal contact with the solid state light source and the thermally conductive component of the lighting fixture so as to spread heat from the solid state light source in a preferential direction from the solid state light source to said thermally conductive component.
US20080062689 filed by Villard teaches an LED lighting fixture which includes a support plate having a first surface and a second surface, a plurality of panels connected to the first surface, in which each panel has an array of LEDs mounted to a planar surface thereof, and a power supply provided on the second surface of the support plate for driving the LED arrays.
U.S. Pat. No. 7,488,093 to Huang, et al. teaches an LED lamp which includes a frame, LED module, a heat sink and a cover. The LED module has a plurality of LEDs. The heat sink is mounted on the frame. The heat sink is attached to a side of the LED module for dissipating heat generated by the LEDs of the LED module. A heat pipe interconnects the heat sink and the cover. The cover is secured so as to shield a top portion of the heat sink and space from the top portion of the heat sink. In addition to the heat sink which can dissipate the heat generated by the LEDs, the heat is also dissipated by the cover via the heat pipe.
US20080231201 filed by Higley et al teaches a (LED) lighting fixture which comprising: a main housing having a bottom surface supporting an array of LEDs, a top surface and sides, at least one driver provided in a side housing attached to a side of the main housing to drive the LED array, the thickness of the driver housing equal to or greater than the thickness of the main housing, and plurality of heat spreading fins arranged on the top surface of the main housing.
The inventions mentioned above do not address the needs of customizability, fast production, maintenance, precision dimensional accuracy and affordability of the SSL fixture based lighting solution.
Thus, in the light of the above mentioned background of the art, it is evident that, there is a need for a solid-state lighting solution which:                provides efficient heat dissipation;        can be thermally efficient;        provides efficient power utilization;        can be environmental friendly;        can be custom manufactured with high degree of speed and flexibility;        can be easily serviceable; and        can be easily installed.        is affordable and low cost        can combat global warming        